US man surrenders after 8 found dead in house

David Conley, 48, is seen in an undated picture released by the Harris County Sheriff's Office in Texas (Reuters)

A man who engaged police in a stand-off at a Texas home has been charged with murder after the bullet-riddled bodies of six children and two adults were found inside, officials say.

The eight people were discovered Saturday (local time) by deputies performing a welfare check at the Houston-area residence after a concerned relative requested the search, officials with the Harris County Sheriff's Office said.

The victims were found in each of the house's three bedrooms. They had been shot, some multiple times, and many were restrained with metal handcuffs, lead investigator Sergeant Craig Clopton told reporters.

The deputies initially tried to contact residents inside the home before spotting a child's body through a window, Chief Deputy Tim Cannon told reporters.

They then forced their way in and were peppered with gunfire and withdrew. Negotiators from a high-risk operations unit later convinced the alleged assailant to surrender, Cannon said.

Police have identified the man as David Conley, 48, a former domestic partner of Valerie Jackson, who died in the attack.

Jackson, 40, also lived in the house where she, her husband and children were killed.

"There was a prior relationship" between Conley and Jackson and at least one of the dead children, the oldest, could be Conley's, Clopton said.

"The killer's motives appear to be related to the dispute with Valerie," Cannon said.

"It's obvious he had some distaste for what was going on within his personal life and his family life," he added.

A prior warrant was already outstanding for Conley related to assault of family members, the police said.

Conley's history of domestic violence dates back to at least 2000, the Houston Chronicle reported, and he had previously threatened and attacked Jackson.

Conley has been charged with three counts of murder, with some of the counts covering multiple killings. He is being held without bond.

"We do not, and cannot, fully comprehend the motive of someone who would take the lives of so many innocent people, especially the lives of the young ones," Cannon said, adding that police would conduct a thorough investigation into the grisly killings.

"This case is in its initial stages, we have a long way to go," he said.

The children ranged in age from six to 13. Three of the victims were female and five were male. All are believed to have died on Saturday, Clopton said.

Earlier, police reports stated that five children and three adults had died, and that Conley was 49.